for OS X

QuickProject is ...

QuickProject is an outline form (hierarchical) things-to-do list.
You can define projects. Projects can be divided into tasks. Tasks can be divided
into subtasks. You can record the percentage completion at the project level, and
at any task or subtask level. You can attach lengthy notes to each individual task
or subtask. Responsibility can be assigned to an individual. Individuals can be selected
from your Apple Address Book.

Version 1.0 ...

We have plans for this software. What additional features would
you want? Let us know.